The invention relates to a filter device comprising a housing in which at least one filter element is arranged that comprises an interior surrounded by a filter material and that is flowed through by a raw gas from the exterior to the interior. The filter device comprises further a cleaning device that comprises at least one compressed air line provided with an outlet opening wherein compressed air flowing out of the outlet opening loads the filter element from the interior. The invention also concerns a method for cleaning at least one filter element, in particular by using a filter device of the aforementioned kind.
Raw gas that contains contaminants is passed through the filter elements. The filter elements retain the contaminants while the raw gas passes through the filter element and is sucked off as clean gas. Over time, the exterior side of the filter element will become clogged with contaminants so that cleaning is required. For this purpose, compressed air is blown through the filter element in a direction opposite to the direction of the raw gas flow so that the contaminants that are adhering to the exterior side of the filter element are removed. In order for the compressed air to act on the entire filter surface area, the outlet opening must have an appropriately large distance from the filter element so that the compressed air stream exiting from the outlet opening can act on the entire filter surface area. When the filter elements have a large diameter, correspondingly large distances between the outlet opening and the filter element are required. Accordingly, a significant mounting space for the filter elements and the associated cleaning device is required. During the cleaning process, the supply of raw gas must be interrupted. This has a negative effect on the efficiency of the filter device.